#include<iostream>
#include<vector>
#include<queue>
#include<cstring>
#include<cmath>
#include<map>
#include<set>
#include<cstdio>
#include<algorithm>
#define debug(a) cout<<#a<<"="<<a<<endl;
using namespace std;
const int maxn=2e5+1000;
typedef long long LL;
inline LL read(){LL x=0,f=1;char ch=getchar();	while (!isdigit(ch)){if (ch=='-') f=-1;ch=getchar();}while (isdigit(ch)){x=x*10+ch-48;ch=getchar();}
return x*f;}
struct P{ LL val,id;};
bool cmp(P A,P B){ return A.val>B.val; }
bool vis[maxn];
int main(void){
   cin.tie(0);std::ios::sync_with_stdio(false);
   LL T;cin>>T;
   while(T--){
      LL m;cin>>m;
      for(LL i=0;i<m+10;i++) vis[i]=0;
      vector<P>res;
      for(LL i=1;i<=m;i++){
          LL x;cin>>x;
          res.push_back({x,i});
      }
      sort(res.begin(),res.end(),cmp);
      LL cnt=(1<<30);
      for(LL i=0;i<res.size();i++){
          if(cnt>=(1LL<<res[i].val)){
             cnt-=(1LL<<res[i].val);
             vis[res[i].id]=true;
          }
      }
      if(cnt){
         cout<<"impossible"<<"\n";
      }
      else{
         for(LL i=1;i<=m;i++){
             if(vis[i]) cout<<1;
             else cout<<0;
         }
         cout<<"\n";
      }
   }
   return 0;
}
